Sonny Bill Williams has spoken out after this afternoon's mass shooting in Christchurch.

Police have confirmed multiple fatalities after shootings at two mosques in Christchurch.

Taking to Twitter, Williams - who is a Muslim himself - expressed his condolences to those affected by the tragedy.

"Just heard the news," an emotional Williams began.

"I couldn't put into words how I'm feeling right now.

"Sending my duas (supplication) to the families. Just sending my duas to your loved ones.

"Inshallah, you guys are all in paradise. I'm just deeply, deeply saddened that this would happen in New Zealand."